In a conductive layer fabrication method, a lower resist layer (210) is
formed on a semiconductor substrate. A water soluble resin layer (212) is
formed over the lower resist layer. Heat treatment is performed so as to
produce a cross-linking layer (211) between the lower resist layer and
the water soluble resin layer, the cross-linking layer being insoluble in
an organic material. A resist containing a photosensitizing agent is
applied to form an upper resist layer (214) over the cross-linking layer.
The upper and lower resist layers are irradiated by a beam through a
photomask. A portion of the upper resist layer and a portion of the
cross-linking layer are removed through development to form an upper
opening. A portion of the lower resist layer is removed using a developer
to form a lower opening. Then a conductive layer (302) is formed on the
semiconductor substrate through the upper and lower openings.